Biopsy needle instrument

ABSTRACT

An automated fine needle biopsy device is described for extracting tissue from the body predominantly in suspected cases of breast cancer. However, it can be used in other parts of the body accessible to needle biopsy. The device causes a fine needle, which is attached to the device, to reciprocate and/or rotate at the same time causing tissue to enter the needle. The depth and number of the thrusts can be pre-programmed, and the force behind each thrust is constant. Suction may or may not be used. The tissue extracted is subsequently expelled onto glass slides for microscopic interpretation. This device and method offer a vast improvement over the present method for fine needle biopsy wherein it is performed manually and in a very haphazard way. The prime deficiency of the manual method currently used is insufficient tissue extraction. This device will correct that situation enabling accurate diagnosis to be made on adequate tissue samples obtained. No similar device is known to be in clinical use at the present time.

[0001] The present application claims the benefit of U.S. ProvisionalApplication No. 60/125,730, filed Mar. 23, 1999, the disclosure of whichis hereby incorporated by reference.

[0002] The present invention relates in general to the field of medicalbiopsy instruments, and more particularly, to such instruments for usein fine needle biopsy of human or animal tissue for medical diagnosticsand the like.

BACKGROUND OF THE INVENTION

[0003] Biopsy instruments are often used to obtain tissue samples formicroscopic examination to test for malignancy or other diseases andabnormalities. Generally, biopsies may be guided by either stereotacticmeans, CAT scan or ultrasound means. Image-guided biopsy procedures areparticularly useful for non-surgical diagnosis of benign and malignantmasses. The biopsy itself may be either a core biopsy or a fine needleaspiration biopsy. For example, an instrument for performingpercutaneous biopsy procedures and collection of soft tissue isdisclosed in Ritchant, et al., U.S. Pat. No. 5,649,547.

[0004] Other currently used biopsy instruments and methods include thosedisclosed in Siczek, et al., U.S. Pat. No. 5,415,169 and Assa, U.S. Pat.No. 5,240,011, Siczek, et al. and Assa each disclose a motorized biopsyneedle positioner employed in a mammographic needle biopsy system forreceiving coordinate information representative of an identified pointof interest within the patient's captive breast under examination andautomatically positioning a biopsy needle in accordance with thecoordinate information to permit insertion of the biopsy needle to theidentified point of interest.

[0005] Additionally, Clement, et al., U.S. Pat. No. 5,368,045 disclosesa handheld biopsy needle instrument employing combined stylets andcannulas capable of taking multiple specimens while the other hand isfree to manipulate an ultrasound probe. The stylet and cannulas arespring loaded, which upon firing, will penetrate the tissue forobtaining a biopsy specimen. A similar biopsy instrument having aplurality of stylets and cannulas which can be controlled independentlyfor capturing a plurality of discreet specimens at a controlled depth isdisclosed in Chin, et al., U.S. Pat. No. 5,415,182. See also Akerfeldt,U.S. Pat. No. 4,944,308.

[0006] Fine needle aspiration biopsy is often performed on a potentiallymalignant mass for confirmation of diagnosis prior to surgery, on morethan one mass where multi-focal or multi-centric malignant disease issuspected, on a suspected benign lesion such as a fibroadenoma, wherethere is ambivalence about follow-up versus excision, or on anultrasound imaged structure with features unlike a simple cyst. Amongthe benefits of fine needle aspiration when compared with other biopsyprocedures are that it is less invasive, requires no incision, causesminimal discomfort, takes less time and costs considerably less. Adiscussion of fine needle aspiration is disclosed in the article FineNeedle Aspiration, Kathleen M. Harris, M.D., FACR, pp. 101-105.

[0007] Suction and capillary methods of aspiration have been successfulon the breast. For suction aspiration, a syringe in a resting positionis attached to a sampling needle. Suction is created by pulling theplunger of the syringe. In the capillary method, a syringe is not usedand suction is not applied. With both methods, up to the present timethe sampling needle is manually moved back and forth rapidly by thephysician within the area to be studied. The needle is further angled inmultiple directions to sample a cone-shaped area within the area to bestudied. In the suction method, the suction should be maintained untilmaterial is visible in the plastic needle hub, or for a minimum oftwenty up-and-down motions in varying directions. This method isdescribed further in Interventional Breast Procedures, edited by D.David Dershaw, pp. 91, 94 and 95. A similar technique is described inGeneral Ultrasound, Ed., Carol A. Mittelstaedt, M.D., pg. 18. Thetechnique is also described in Interventional Breast Ultrasonography,Ellen B. Mendelson, M.D., pp. 57-76. Another similar technique is thatdiscussed in Thyroid and Parathyroid, pg. 107.

[0008] Until now, and as described in the foregoing references, fineneedle aspiration biopsies have been performed manually. Such aprocedure involves manually thrusting a needle alone or a needleattached to a syringe, with or without suction. The procedure isgenerally random in that the depth of the thrusts, number of thrusts,the area covered and the force used are done in a very haphazard way.For example, one thrust could be 5 millimeters, while another could be 2millimeters and so forth.

[0009] A significant limitation with random depth is that when a lesionis very small in diameter, there are occasions where none or a few ofthe thrusts obtain the necessary tissue sample. One of the thrusts maybe directed to a lesion, but may bypass the lesion completely as aresult of a lack of consistent direction of the thrusts. Random depthresults in a significant amount of fine needle aspiration biopsiesretrieving an insufficient amount of tissue with which to do anappropriate diagnostic evaluation. If the number of thrusts is limited,this compounds the problem further and increases the chances of missingthe lesion.

[0010] Another limitation of the prior method is lack of significantthrusting energy. The force behind the thrust may be variable, and manymay be insufficient enough to pierce the outer margins of certainlesions, especially fibroadenomas. The needle can potentially bounce offthe fibroadenoma or push it aside rather than pierce the outer marginand obtain the necessary tissue.

[0011] Many fibroadenomas are currently surgically excised without anyattempt to perform a fine needle biopsy. The cost of excisional biopsiesare multiple times the cost of a fine needle aspiration biopsy.Significant medical financial resources could be saved by performingfine needle aspiration biopsies instead of excisional biopsies.Providing an improved method and an automated biopsy instrument forperforming fine needle aspiration biopsies would reduce the need forexcisional biopsies together with their inherent risks.

[0012] There is disclosed in Dejter, Jr., et al., U.S. Pat. Nos.5,060,658 and 4,989,614 a medical instrument for fine needle aspirationbiopsies of the prostate only. The biopsy instrument includes a needlehaving an opening which can be occluded by a stylet during both thepenetration and withdrawal stage of an aspiration cycle during thebiopsy procedure. After penetration of the target tissue, the needle isreciprocated a predetermined number of times as determined by thedesired cytological sample yield. During the reciprocating procedure,the needle opening remains unoccluded by withdrawal of the stylet.Tissue sample is collected in a syringe under vacuum. After sufficienttissue sample has been collected, the stylet is returned to its forwardposition, thereby occluding the needle opening prior to withdrawal ofthe needle from the patient. The biopsy instrument is opened in order toremove the syringe containing the collected tissue sample forcytological analysis.

[0013] Naslund, U.S. Pat. No. 4,605,011 discloses a biopsy instrumentfor taking samples of cells of small tumors using fine needle puncturingtechniques. The biopsy instrument includes a hand grip having a syringeprovided with a removable cannula. The cannula is connected to a motorwhich is operative for driving the cannula in an oscillating,recipricatory motion. The motor is constructed as an electromagnethaving pole elements, which when energized, cause reciprocal motion of apole element which is coupled to the cannula. The cannula is connectedto a container which is placed under vacuum for drawing a tissue samplefrom the cannula during the biopsy procedure. This instrument is notused without suction.

[0014] Patipa, et al., U.S. Pat. No. 4,644,952 discloses a surgicaloperating instrument provided with a needle which can be reciprocated bymeans of a cam and cam follower arrangement. The needle is attached toone end of a shaft, the other end supporting a laterally extending camfollower. The cam follower is captured interiorly within a cam betweentwo opposing cam surfaces. The cam is rotated by a motor therebyeffecting reciprocal motion of the needle. There is no stated use forthe instrument disclosed in Patipa, et al.

[0015] The instruments disclosed in Dejter, Jr., et al., Naslund andPatipa, et al., although effecting reciprocal motion of the needle orcannula, have designs which provide disadvantages in fine needle biopsyprocedures. For example, in certain cases the disclosed designs arecomplicated and therefore expensive to manufacture, do not provideaccurate control of the reciprocal motion and thrust force required offine needle biopsy procedures, are bulky or cumbersome in size makingthe instrument difficult to handle during the biopsy procedure, requirethe use of a stylet, or are not suitable for vacuum collection of atissue sample. Similar disadvantages are known from a medical instrumentwhich effects reciprocal motion of a needle by a rotating cam and springarrangement. The cam is operative for advancing the needle in a forwarddirection, the return motion being effected by a compression spring.

[0016] There is accordingly the need for improvements in fine needlebiopsy instruments which provide reciprocal and/or rotational motion ofthe needle to collect tissue samples for medical diagnostics in anaccurate and efficient manner, while being suitable for use in variousenvironments such as hospitals and the like.

SUMMARY OF THE INVENTION

[0017] The present invention broadly addresses the need for improvedquality and completeness of technique, as well as an improved instrumentfor obtaining tissue samples through fine needle biopsy.

[0018] The present invention involves the use of fine needle biopsytechniques with a biopsy needle instrument that may be programmed toprovide a predetermined depth and number of thrusts, a predeterminedthrust cycle, a predetermined pattern and/or area to be covered, and apredetermined force of thrust. By manually changing slightly the angleof the device with the needle, multiple areas of the tumor can besampled in a very short period of time. The needle or syringe isattached to a small handheld device, which can be driven by a smallelectric motor or hydraulic fluid, e.g., compressed air and the like.The needle can move in a “jackhammer” type fashion to implement theprogrammed settings for depth, number, cycles and force of thrusts. Theforce behind each thrust could be constant and of sufficient magnitudeto pierce the outer margin of a small lesion such as a fibroadenomarather than pushing them aside because of insufficient force. The devicecan be used with or without suction for aspiration of the tissue sample.Since all the functions of the instrument can be predetermined andpreprogrammed, the physician can start the procedure, focus on theultrasound monitor and then position the needle in juxtaposition to thelesion. The invention also incorporates a safety mechanism or “deadmanswitch” to prevent accidental initiation of the reciprocal action of theneedle prior to the actual biopsy.

[0019] The fine needle aspiration biopsy instrument in accordance withthe present invention generally includes a powered handpiece, a biopsyneedle to be inserted into the handpiece, an internal programmablecontroller or remote programmable computer for controlling theinstrument, a power source for operation of the instrument and a suctionsource. As will be understood from a further description of the presentinvention, the suction connection is an optional feature.

[0020] The instrument to which the biopsy needle is attached isoperative to provide at least one, and preferably two motions to thebiopsy needle. Specifically, the instrument incorporates a jack-hammertype motion that causes a reciprocal thrusting motion of the biopsyneedle into the tissue to be biopsied, and optionally, a rotary motionof the biopsy needle which will produce a cutting effect.

[0021] The power source is operative for providing the necessary powerfor operating the instrument to affect the reciprocal and/or rotary typemotion of the biopsy needle by means of, for example, an electric orpneumatic operated motor for operation of a reciprocating/rotatingassembly as disclosed pursuant to the present invention. In addition tothe thrusting or reciprocal motion, the biopsy needle may also berotated or manipulated about an orbital pattern as opposed to rotationalong its longitudinal axis, which is also contemplated pursuant to thepresent invention. Further in this regard, a suitable cam assembly orother such mechanism can be inserted into the handpiece to affectorbital rotation of the biopsy needle in a predetermined pattern, forexample, oval, circular, random, zig-zag, rectangular and the like. Inuse, the thrusting action of the biopsy needle will orbit such that thepattern of specimens taken of the tissue sample will correspond to thepredetermined pattern defined by the cam assembly or other suchmechanism in the instrument. It is therefore possible for the instrumentto sample the tissue at a plurality of random or predetermined locationsto ensure that the area from which specimens are to be taken isadequately sampled.

[0022] The programmable controller or computer may be set according tothe desired parameters either before or after insertion of the needleinto the patient. When the physician is ready for the sample to betaken, he or she may activate the instrument by turning a switch thatcontrols the power source, e.g., electricity or hydraulic source. As thesample is being taken, the physician is free to focus on the ultrasoundmonitor which will demonstrate the lesion together with the needlewithin it. By focusing on the monitor, this ensures that the tissueextracted is from the lesion itself and not from the surroundingtissues.

[0023] A programmable device for use in association with the instrumentpermits programming of the depth of thrusts, the number of thrusts perunit of time, the area or pattern of thrusts, the force of the thrusts,as well as other variable options to specifically select desiredparameters. A programmable device may be provided within the handpieceitself or may be remote therefrom such as using a programmable computer.

[0024] By way of one illustrative example, the biopsy needle used forfine needle aspiration may range from 20 gauge to 25 gauge, having a 4.0mm stroke length, a zig-zag area pattern, e.g., 2-6 mm travel betweenthrusts and 10-20 strokes per second for 5 seconds. The biopsy needlemay be connected to the handpiece using any suitable connector which iswell known in the medical field and the aforementioned cited prior art.

[0025] It can be appreciated from the foregoing description of thebiopsy needle instrument in accordance with the present invention, thatthe physician can program the instrument to accommodate any specifictissue or lesion to be biopsied with a number of variable parameters toensure that sufficient samples of tissue for biopsy are obtained. Oncethe specimen has been obtained, with or without suction, into the biopsyneedle, the specimen can be extracted into a jar of preservative fluidor onto a slide for analysis.

[0026] In accordance with one embodiment of the present invention thereis described a medical instrument comprising a housing having an openingat one end thereof; a first shaft within the housing for reciprocalmotion, the first shaft having a front section and a rear section, thefront section of the shaft extending adjacent the opening in thehousing; a cam assembly within the housing, the cam assembly comprisingfirst and second cam followers arranged in spaced apart relationship onthe first shaft, a cam arranged between the first and second camfollowers mounted on a rotatable second shaft, the cam having outwardlyfacing first and second cam profiles respectively engaging an opposingone of the first and second cam followers, whereby the cam assembly uponrotation of the cam converting rotating motion of the second shaft toreciprocal motion of the first shaft.

[0027] In accordance with another embodiment of the present inventionthere is described a medical instrument comprising a housing having anopening at one end thereof; a reciprocating shaft within the housing,the reciprocating shaft having a front section and a rear section, thefront section of the shaft extending outwardly through the opening; acam assembly within the housing operatively coupled to the reciprocatingshaft, the cam assembly comprising a cam having first and second spacedapart outwardly facing cam profiles, a first cam follower on one side ofthe cam in engagement with the first cam profile, and a second camfollower on the other side of the cam in engagement with the second camprofile; and a motor operatively coupled to the cam for rotationalmovement of the cam, whereby the engagement of the first and second camprofiles with the first and second cam followers during rotation of thecam causes reciprocal movement of the reciprocating shaft.

[0028] In accordance with another embodiment of the present inventionthere is described a medical instrument comprising a housing having anopening at one end thereof; a reciprocating shaft along a first axiswithin the housing, the reciprocating shaft having a front section and arear section, the front section of the shaft extending outwardly throughthe opening; a cam assembly within the housing comprising a cam havingfirst and second spaced apart cam profiles, a first cam follower on oneside of the cam in engagement with the first cam profile, and a secondcam follower on the other side of the cam in engagement with the secondcam profile; and a motor on a second axis within the housing operativelycoupled to the cam for rotational movement of the cam, the second axisoffset from the first axis, whereby rotation of the cam causesreciprocal movement of the reciprocating shaft.

[0029] In accordance with another embodiment of the present inventionthere is described a medical instrument comprising a housing having anopening at one end thereof; a shaft within the housing for reciprocalmotion, the shaft having a front section and a rear section, the frontsection of the shaft extending outwardly through the opening of thehousing; a motor within the housing; and a cam assembly within thehousing comprising a cam operationally coupled to the motor forrotational movement of the cam, the cam having a track and a camfollower fixed to the housing and received within the track; wherebyreceipt of the cam within the track during rotation of the cam by themotor causes reciprocal movement of the shaft.

BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The above description, as well as further objects, features andadvantages of the present invention will be more fully understood withreference to the following detailed description of a biopsy needleinstrument, when taken in conjunction with the accompanying drawingswherein:

[0031]FIG. 1 is a perspective view of a needle biopsy instrumentconstructed in accordance with one embodiment of the present invention;

[0032]FIG. 2 is an exploded perspective view of the needle biopsyinstrument showing its component parts including a cam assembly inoperative assembled relationship;

[0033]FIG. 2A is a perspective view of a pair of pins designed as camfollowers in accordance with one embodiment of the present invention;

[0034]FIGS. 3A and 3B are front elevational views showing the camassembly in sequential operative positions for effecting reciprocalmotion of the needle carrying shaft;

[0035]FIG. 4 is a diagrammatic illustration of a needle biopsyinstrument constructed in accordance with another embodiment of thepresent invention;

[0036]FIG. 5 is a cross-sectional view taken along line 5-5 in FIG. 4showing a coupling arrangement;

[0037]FIG. 6 is a cross-sectional view showing a coupling arrangementconstructed in accordance with another embodiment of the presentinvention;

[0038]FIG. 7 is a perspective view of a reciprocating assembly for usein the needle biopsy instrument constructed in accordance with anotherembodiment of the present invention;

[0039]FIG. 8 is a perspective view of a reciprocating assembly for usein the needle biopsy instrument constructed in accordance with stillanother embodiment of the present invention;

[0040]FIG. 9 is a perspective view of a reciprocating assembly for usein the needle biopsy instrument constructed in accordance with yet stillanother embodiment of the present invention;

[0041]FIG. 10 is a diagrammatic illustration of a needle biopsyinstrument constructed in accordance with another embodiment of thepresent invention;

[0042]FIG. 11 is a diagrammatic illustration of a needle biopsyinstrument constructed in accordance with still another embodiment ofthe present invention;

[0043]FIG. 12 is a schematic illustration of one embodiment of anelectronic control circuit for operation of the needle biopsyinstrument;

[0044]FIG. 13 is a perspective view of the needle biopsy instrumentconnected to a vacuum source for collecting tissue samples during thebiopsy procedure;

[0045]FIG. 14 is a graph illustrating the needle travel displacement forone revolution of the cam constructed in accordance with one embodimentof the present invention;

[0046]FIG. 15 is a profile of a cam constructed in accordance withanother embodiment of the present invention;

[0047]FIG. 16 is a graph illustrating the needle travel displacement forone revolution of the cam as shown in FIG. 15 in accordance with anotherembodiment of the present invention;

[0048]FIG. 17 is a graph illustrating the needle travel displacement forone revolution of a cam constructed in accordance with anotherembodiment of the present invention;

[0049]FIG. 18 is a graph illustrating the needle travel displacement forone revolution of a cam constructed in accordance with still anotherembodiment of the present invention;

[0050]FIG. 19 is a graph illustrating the needle travel displacement forone revolution of the cam constructed in accordance with yet stillanother embodiment of the present invention;

[0051]FIG. 20 is a partial cross-sectional view showing the profile of acam constructed in accordance with another embodiment of the presentinvention;

[0052]FIG. 21 is a front elevational view showing a cam assemblyconstructed in accordance with another embodiment of the presentinvention;

[0053]FIG. 22 is a front elevational view showing a cam assemblyconstructed in accordance with another embodiment of the presentinvention;

[0054]FIG. 23 is a front elevational view showing a cam assemblyconstructed in accordance with another embodiment of the presentinvention;

[0055]FIG. 24 is a front elevational view showing a cam assemblyconstructed in accordance with another embodiment of the presentinvention;

[0056]FIG. 25 is a front elevational view showing a cam assemblyconstructed in accordance with another embodiment of the presentinvention;

[0057]FIG. 26 is a front elevational view showing a cam assemblyconstructed in accordance with another embodiment of the presentinvention;

[0058]FIG. 27 is a front elevational view showing a cam assemblyconstructed in accordance with another embodiment of the presentinvention;

[0059]FIG. 28 is a front elevational view showing a cam assemblyconstructed in accordance with another embodiment of the presentinvention;

[0060]FIG. 29 is a front elevational view showing a cam assemblyconstructed in accordance with another embodiment of the presentinvention; and

[0061]FIG. 30 is a front elevational view showing a cam assemblyconstructed in accordance with another embodiment of the presentinvention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0062] One of the most dreaded diseases in the world today is breastcancer. In this country alone, there are over 200,000 new casesdiagnosed every year, and there are approximately 45,000-50,000 deathsper year. The optimum chance for survival depends upon early detection,diagnosis and treatment. The best method of detection is mammography.Diagnosis depends upon biopsy, and treatment consists mainly of surgery,chemotherapy and radiation therapy.

[0063] There are four methods of biopsy—surgical excision, stereotacticlarge core biopsy, large core biopsy “guns” and fine needle biopsy withor without suction.

[0064] There are approximately 1-1.2 million breast biopsy proceduresperformed per year in this country alone. Approximately 80-90% of themturn out to be benign. With this in mind, it should be the goal of anybiopsy procedure to provide as accurate a diagnosis as possible. Inaddition, it should be as minimally traumatic to the patient aspossible, and as least expensive as possible. The biopsy procedure thataddresses these matters the best is fine needle biopsy. Surgicalexcision means a surgical procedure with anesthesia, skin incisions, andpatient morbidity. It is the most expensive of the biopsy procedures.Stereotactic and large core biopsy gun procedures utilize large needles,some as large as 11 gauge, as well as anesthesia, skin incisions andpatient morbidity.

[0065] Fine needle biopsy, with or without suction, can provide anaccurate diagnosis. It is almost completely atraumatic with very little,if any, patient morbidity. It does not require anesthesia. There is noskin incision. It takes only one needle insertion through the skin. Theneedle size ranges between 20-25 gauge. The procedure is very rapid, 5to 10 minutes at most. It is the least expensive of the biopsyprocedures, and the diagnosis should be available the day following theprocedure. As an example, a woman could have a diagnostic or screeningmammogram on a certain day. If a lesion is found, it can be biopsied thesame day, and she can have an answer the following day. At the presenttime, she may have to wait weeks between the mammogram and the answer toa biopsy procedure.

[0066] At the present time, FNA or fine needle aspiration biopsies areperformed manually. This involves the manual thrusting of a needle aloneor a needle attached to a syringe with or without suction. This is arandom procedure in that the depth of the thrusts and the area to bebiopsied are done in a very haphazard way. For example, one thrust couldbe 8 mm, another 1.5 cm, another 4 mm and another 1.5 mm. The lesion maybe only 5-6 mm in diameter, and it is possible that only 20-30% or evenless of the thrusts may actually obtain tissue. The biggest deficiencyof fine needle biopsy as it exists up to now is the lack of sufficienttissue extracted. Therefore, lack of consistent direction and depth is amajor deficiency of the present procedure. A second problem up to now isthe lack of consistent and sufficient thrusting force. The widevariability in thrusting force could lead to the inability of the needleto pierce the outer margins of certain lesions such as fibroadenomas.The needle may bounce off of the fibroadenoma or push it aside and, assuch, no tissue may be extracted.

[0067] The purpose of the proposed biopsy device is to perform fineneedle biopsies with a programmable device whereby the depth of thethrusts are pre-determined and controlled. In addition, the force behindeach thrust is constant and sufficient to pierce the outer margins ofcertain lesions such as fibroadenomas rather than pushing them aside.Other options would include a rotatory motion of the needle to produce acutting effect as well as a pre-programmed area pattern to be biopsiedsuch as a circular or zigzag pattern.

[0068] The needle or syringe would be attached to a small hand-helddevice. The device would function similar to a jackhammer, producingrapid oscillatory thrusts of the needle. Multiple thrusts would beaccomplished with pre-programmed depth settings and possiblepre-programmed patterned areas. For example, a series of 10-20 thrustscould be performed directed at one point, or a series of 20 thrusts oreven 50 thrusts could be directed in a circular pattern. The thrustscould be programmed to travel 2 mm, 4 mm, 6 mm, whichever one chooses.There may be suction or no suction.

[0069] A general description of the actual procedure is as follows. Amass in the breast is identified by ultrasound. A fine needle attachedto the device is now introduced into the breast under ultrasoundguidance. The needle is advanced to the lesion, and the tip of theneedle pierces the outer rim of the lesion. The device is now activated,and a series of 10-20 thrusts/second is accomplished for 2-3 seconds.The device is now angled slightly while still in the lesion, and thedevice is activated again for 2-3 seconds. This can be done 4-5 times sothat the whole lesion is biopsied. The needle and device are thenremoved from the breast. The tissue is extracted from the needle, put ona slide and sent to the pathologist or cytologist for interpretation.The whole procedure should take no more than 5-10 minutes. There is noincision, no anesthesia, and no morbidity to speak of.

[0070] At the present time, stereotactic biopsies are performed in apre-programmed direction and depth, by only one thrust is made at a timewith removal of multiple large cores. The original stereotactic unitcosts $400-500,000. One needs a dedicated room, technicians and nurses.It also utilizes X-rays to localize the lesion. Biopsy guns use largecore needles, and anesthesia is necessary. As stated already, only onethrust is accomplished at each “firing” of the gun.

[0071] As stated in many articles on needle biopsy procedures, any solidlesion that could be visualized with ultrasound should be biopsied witha fine needle. Calcifications, a possible sign of malignancy, cannot beseen adequately with ultrasound and should therefore be biopsied withlarge-gauge biopsy devices.

[0072] Many fibroadenomas, which are benign lesions, are now surgicallyexcised without any attempt at needle biopsy. The cost of anexcisional-biopsy is many times the cost of a fine needle biopsy.Millions of medical dollars could be saved performing fine needlebiopsies instead of excisional biopsies. This could be accomplished iffine needle biopsies are made reliable. An automated fine needle biopsydevice will greatly enhance the reliability of fine needle biopsies.

[0073] The most common application will be for breast lesions, but itshould be understood that the device can be used wherever fine needlebiopsies are now performed, including chest, abdomen, pelvis, neck(thyroid), axilla, etc. It can also be utilized in veterinary medicine.

[0074] In summary, the most common deficiency with fine needle biopsy upto the present is insufficient tissue extraction. The automated fineneedle biopsy device as described pursuant to the present invention willcorrect that problem. The procedure is rapid, cost effective, almostcompletely without morbidity, and when adequate tissue is obtained, adiagnosis will be possible in virtually every case.

[0075] There is no similar device in use today for doing fine needlebiopsies. Stereotactic and large-core biopsy guns have many drawbacks asoutlined. By automating the fine needle biopsy procedure that is nowdone manually, it is felt that the shortcomings of this procedure asperformed up to now will be corrected. As a result of this, thereliability of this procedure can be assured.

[0076] In describing the preferred embodiments of the subject matterillustrated and to be described with respect to the drawings, specificterminology will be utilized for the sake of clarity. However, theinvention is not intended to be limited to the specific terms soselected and is to be understood that each specific term includes alltechnical equivalents which operate in a similar manner to accomplish asimilar purpose.

[0077] Referring now to the drawings, where like reference numeralsrepresent like elements, there is shown in FIG. 1 a perspective view ofa needle biopsy instrument designated generally by reference numeral100. The instrument 100 is constructed from an elongated housing 102having a right half 104 and a left half 106. Extending outwardly throughthe housing 102 at one end thereof is a master on/off switch 108. In asimilar manner, a “deadman” switch 110 extends outwardly from thehousing 102 at the other end thereof. The forward end 112 of the housing102 is provided with an opening 114 through which there extends anelongated shaft 116. The opening 114 is covered by a flexible boot 118through which the shaft 116 extends. The boot 118 can be constructed ofsuitable polymer materials well known in the medical instrument art. Acoupling device 120 is attached to the end of the shaft 116 forreleasably securing a needle 122 thereto. In the preferred embodiment,the coupling device 120 is integrally formed as one unit with the needle122 for attachment to the instrument 100. In the preferred embodiment,the needle 122 which will be used for fine needle biopsy procedures,will preferably have a size in the range of about 20-25 gauge. However,other size needles may be used with the instrument 100 of the presentinvention. The instrument 100 may be connected to a remote computer 124and/or be provided with an internal programmable microprocessor 126 foroperation of the instrument 100. The microprocessor 126 can be connectedto the computer 124 using any similar data link 128.

[0078] Referring to FIG. 2, the instrument 100 includes a motor 130which may be electric or hydraulic. In the case of hydraulic, the motor130 may be driven by an air or liquid feed supply (not shown) which canbe external to the housing 102 or provided internally by means of, forexample, a compressed air source. In the illustrated embodiment, themotor 130 is in the nature of an electric motor which is powered by abattery source 132. The battery source 132 may be in the nature ofrechargeable batteries, or conventional disposable batteries. Also, thepower source can be household AC voltage or DC voltage through use of aconverter. In either event, the battery source 132 is operative of themotor 130. The motor 130 is of known design in the medical instrumentsfield, for example, those having rpm in the range of about 200-2000,which can provide 20 strokes in the range of 0.6-6 seconds. It is to beunderstood that the foregoing particulars of the motor 130 are by way ofexample only, and other rpm's and stroke frequencies may be incorporatedinto the instrument 100 in accordance with the present invention.

[0079] The motor 130 may include a gear box 134 to provide the desiredrotational speed and torque for use in the instrument 100. The motor 130via the gear box 134, is operative for rotation of a shaft 136 coupledthereto. The motor shaft 136 is rotated along its longitudinal axis 138.

[0080] Shaft 116 extends longitudinally through the housing 102underlying motor shaft 136 and a portion of the motor 130. The shaft 116has its longitudinal axis 140 arranged parallel to the longitudinal axis138 of motor shaft 126. Shaft 116 is slidably mounted within the housing102 using any suitable means, such as bearing supports (not shown),molded portions of the housing 102 and the like. The shaft 116 may havea rectangular cross section along all or a portion thereof to precludeits rotation within the housing 102, or a circular cross sectionthroughout where rotation of the shaft is desired during operation ofthe instrument 100. A front section 142 of the shaft 116 extendsoutwardly through opening 114 to which the coupling device 120 isattached. A rear section 144 of the shaft extends underlying the shaft136 where it terminates adjacent a reciprocating shaft positioningswitch 146. Other switches within the instrument 100 include a momentaryactuator switch 148 which is coupled to the deadman switch 110 by meansof a push rod 150 and compression spring 152. A discussion of thedeadman switch 110, positioning switch 146 and momentary actuator switch148 will be described hereinafter.

[0081] A cam assembly 154 is positioned within the housing 102, couplingshaft 136 to shaft 116 at the rear section 144. As further shown inFIGS. 3A and 3B, the cam assembly 154 includes a cam 156 and first andsecond cam followers 158, 160. The cam 156 is constructed in the natureof a cylindrical body 162 having spaced apart surfaces definingoutwardly facing first and second cam profiles 164, 166. The body 162 ofthe cam 156 is mounted to shaft 136 by means of a cylindrical member168. From the foregoing description, rotation of shaft 136 by means ofmotor 130 and gear box 134 will cause cam 156 to rotate about axis 138.

[0082] The first and second cam followers 158, 160 are mounted to theshaft 116. By way of example, each of the cam followers 158, 160 are inthe nature of flat disks or preferably elongated cylindrical pins 161,see FIG. 2A which project upwardly in a generally radial direction fromthe shaft 116 toward cam 156. The spaced apart cam followers 158, 160define an opening 170 therebetween which is sized to receive aperipheral portion of the cam 156. Cam follower 158 is operative forengagement with the first cam profile 164, while the second cam follower160 is operative for engagement with the second cam profile 166. It isto be understood that the cam followers 158, 160, can be any othershaped body which extends outwardly from shaft 116 for engagement withthe first and second cam profiles 164, 166. In this regard, the camfollowers 158, 160 can be separately mounted elements or integrallyformed with the shaft 116.

[0083] As shown in FIGS. 3A and 3B, upon rotation of the cam 156 byoperation of motor 130, the shaft 116 will be caused to reciprocate asthe cam followers 158, 160 ride in engagement with the first and secondcam profiles 164, 166. By altering the first and second cam profiles164, 166, various movements can be effected with respect to the shaft116. For example, the stroke length of the shaft 116 can be changed bychanging the angular relationship between the longitudinal axis 172 ofthe cam 156 with respect to its rotational axis 138. In this regard, thegreater the angle between axes 138, 172, the greater the stroke lengthwill be produced on the shaft 116. A maximum stroke length in the rangeof about 1 cm is contemplated for the instrument 100. However, it is tobe understood that other stroke lengths can be used in biopsy needleinstruments 100 in accordance with the present invention.

[0084] Referring now to FIG. 12, there is illustrated a schematicdrawing of one electronic control circuit for operation of theinstrument 100, the bold circuit lines representing the dynamic brakecircuit for shaft positioning. One side of the on/off switch 108 isconnected to the positive terminal of battery source 132. The other sideof the on/off switch 108 is connected to terminal 174 on motor 130 andto terminal 176 on the positioning switch 146. Terminal 176 is anormally open position of the positioning switch 146. The negative sideof the battery source 132 is connected to terminal 178 on thepositioning switch 146 and to terminal 180 on the momentary actuatorswitch 148. Terminal 178 corresponds to a normally closed position onthe positioning switch 146, while terminal 180 corresponds to a normallyopen position of the momentary actuator switch 148. Closed terminal 182on the positioning switch 146 is connected to normally closed terminal184 on the momentary actuator switch 148. Terminal 186 of the motor 130is connected to terminal 188 on the momentary actuator switch 148,corresponding to a closed position. The momentary actuator switch 148 iscoupled to the deadman switch 110 by means of push rod 150 andcompression spring 152.

[0085] In operation, the deadman switch 110 is closed by depressing samemanually so as to cause push rod 150 to close the connection betweenterminals 180, 188. At the same time, the operator having actuated theon/off switch 108 will allow power from battery source 132 to be fed tothe motor 130 for its operation. In the event of release of the deadmanswitch 110, compression spring 152 will urge push rod 150 away fromengagement with the deadman switch 148 to open the connection betweenterminals 180, 188. However, power to the motor 130 is still providedafter release of the deadman switch 110, through positioning switch 146,until the shaft 16 is in a “home” position.

[0086] The positioning switch 146 is positioned within the housingrearwardly of the shaft 116. The positioning switch 146 has an actuatinglever 190. In the event of a malfunction of the instrument 100, wherebythe stroke length of the shaft 116 is outside a predetermined acceptablerange, the shaft will engage lever 190 so as to open the positioningswitch 146. Normally, the positioning switch 146 is in a closed positionproviding electrical continuity between terminals 178, 182 so as toclose the circuit upon actuation of the momentary actuator switch 148 bymeans of the deadman switch 110. In the event that the positioningswitch 146 is activated by movement of lever 190, the positioning switchwill open thereby disconnecting power to the motor 130. The positioningswitch 146 thereby functions as a safety switch to preclude injury to apatient. In this regard, the positioning switch 146 provides a homeposition for the shaft 116 to ensure that the first thrust of the shaftis outward away from the instrument 100, as opposed to being retractedwithin the instrument. As can be appreciated by the foregoingdescription, actuation of the motor 130 will effect rotation of cam 156to cause reciprocal motion of the shaft 116 as the cam followers 158,160 engage the first and second cam profiles 164, 166. In the event thatthe deadman switch 110 is inactivated by releasing same, and thatactivation of the positioning switch 146 occurs, the motor 130 will stopoperation. Thus, both the deadman switch 110 and the positioning switch146 control the motor 130. In order for the motor 130 to shut off, thedeadman switch 110 must be released and the positioning switch 146 mustbe actuated.

[0087] The instrument 100 may operate in a manual mode, in an on and offfashion, with continued reciprocation of the shaft 116. The instrument100 may also be operated under programmed control according to thedesired parameters selected by the physician. For example, byprogramming the instrument 100, this permits predetermination of thenumber of thrusts, the number of thrusts per unit of time, as well asother variable options to specifically select desired parameters. Theprogrammable aspect of the instrument 100 may be achieved by means of aprogrammed external computer 124 and/or an internal microprocessor 126.In addition, the computer 124 and/or microprocessor 126 may storecritical patient data as well as other diagnostic information.

[0088] Referring now to FIGS. 4-6, another embodiment of a needle biopsyinstrument 192 will now be described wherein like reference numeralsrepresent like elements. A cam 194 is constructed from an elongated body196 having a front section 198 and a rear section 200. The front section198 is provided with a circumferential opening which forms a cam track202 between adjacent sidewalls 204, 206 of the opening. The axis 208 isarranged at an angle to the longitudinal axis 138 of shaft 136 aboutwhich the cam rotates. In other words, the cam profile formed bysidewalls 204, 206 and hence the cam track 202, is arranged at an angleto its axis of rotation. A cam follower 210 is attached to the housing102 and extends into the cam track 202. The cam follower 210 may beconstructed as a projection or pin from the housing 102 having its freeend captured within the opening forming the cam track 202.

[0089] The rear section 200 of the cam 194 is provided with elongatedinternal bore 212. The bore 212 is sized and configured to slidinglyreceive a coupling 214 which is attached to shaft 136. The coupling 214and bore 212 are provided with other than a circular shape, such assquare, triangular, polygonal, oval or the like such that rotation ofthe coupling will effect rotation of the cam 194. In this regard, uponrotation of the coupling 214 by means of the motor 130, the rotarymotion will be transmitted to effect rotation of the cam 194. As the camfollower 210 is captured within the cam track 202, rotation of the cam194 will cause reciprocal motion of the cam. This reciprocal motion istransmitted to the needle 122 which is attached to coupling device 120.The coupling device 120 is attached to shaft 116 which is supported on asupport member 216. To prevent rotation of the support member 216, andhence the needle 122, the support member is maintained in contact withcam 194 by an intervening bearing 218. The bearing 218 will permitrotational motion of the cam 194, while facilitating the prevention ofrotational motion of the support member 216. In this regard, the supportmember 216 and adjacent housing 102 will be provided with a guide pinand linear track arrangement as to be generally described with respectto the FIG. 6 embodiment. This, in turn, will prevent the support member216 from rotating, while at the same time, permitting its reciprocalmovement.

[0090] In an alternate embodiment as shown in FIG. 6, the coupling 220may be in the nature of a cylindrical body which transmits rotationalmotion to the cam 194 by means of an elongated key 222. The bore 212 inthe cam 194 will also be of cylindrical shape. The key 222 is receivedwithin an elongated opening 224 within the coupling 220. As a result,the coupling 220 can slide longitudinally within the bore 212, whiletransmitting rotation of the coupling to the cam 194 as a result of theinterlocking key 222.

[0091] Referring now to FIGS. 7-9, there will be described alternativeassemblies for use in the instrument 100 for effecting reciprocal motionof the needle 122. As shown in FIG. 7, motor 130 is coupled to a firstbeveled gear 226 which is meshed with a second beveled gear 228. Thesecond beveled gear 228 is supported on a plate 230 which is coupled toa push rod 232 attached to a peripheral portion of the plate. The pushrod 232, in turn, is connected to one end of the shaft 116. By rotationof the first and second beveled gears 226, 228, the push rod 232 willeffect reciprocal motion of shaft 116. The shaft 116 slides freelywithin a stationary sleeve 233 which is supported within the housing102.

[0092] Referring now to FIG. 8, the shaft 136 is provided with acontinuous helical groove 234 or gear. The shaft 136 is received withina bore (not shown) extending within one end of the shaft 116. The end ofthe shaft 116 is provided with suitable means for tracking within thehelical groove 234 or engagement with the gear to effect reciprocalmotion of the shaft. Shaft 116 is slidingly received within a stationarysleeve 236 which is provided with outwardly extending elongatedprojections 238. The projections 238 are captured within a correspondingportion of the housing 102 to prevent rotation of the stationary sleeve236. The shaft 116 is provided with similar shaped side projections 240which are slidingly received within the interior opening formed by sideprojections 238 formed within sleeve 236. Based upon this arrangement,shaft 116 will reciprocate freely within sleeve 236 while beingprecluded from rotation by the presence of the side projections 240.

[0093] Turning now to FIG. 9, a pair of C-shaped cam members 242, 244are respectively attached to shafts 136, 116. The C-shaped cams 242, 244have respective cam surfaces 246, 248 which are held in contact witheach other when in assembled relationship by means of, for example, aspring (not shown). By rotation of the C-shaped cam 242, its cam surface246 will track the cam surface 248 on C-shaped cam 244 causingreciprocal motion of shaft 116.

[0094] As thus far described, the biopsy needle instrument of thepresent invention provides reciprocal motion to the attached needle 122.It may also be desirable that the needle 122 be simultaneously rotatedduring its reciprocal motion. Turning to FIG. 10, a needle biopsyinstrument 250 of similar construction to instrument 192 as shown inFIG. 4 is illustrated. The instrument 250 provides both reciprocal androtational motion of shaft 116. In the instrument 250, the shaft 116 isattached to the front section 198 of the cam 194. As previouslydescribed with respect to the instrument 192 of FIG. 4, the shaft 116was separated from the cam 194 by means of bearing 218. By directconnection, rotation of the cam 194 will effect rotation of shaft 116,and hence needle 122, while at the same time, providing reciprocalmotion. Accordingly, it is to be understood that instrument 192 providesreciprocal motion only, while instrument 250 provides both reciprocaland rotary motion.

[0095] Referring now to FIG. 11, a needle biopsy instrument 252 inaccordance with another embodiment of the present invention will now bedescribed which provides both rotary and reciprocal motion to the needle122. A drive gear 252 is coupled to the shaft 136 of the motor 130. Asshown, the rotational axis 138 of the drive gear 252 is arrangedparallel to, and spaced apart, from the rotational and reciprocal axis140 of shaft 116. Shaft 116 is attached centrally to cam 254. Cam 254 isconstructed from a body 256 having two outwardly facing first and secondcam profiles 258, 260. The peripheral edge of the cam 254 is receivedwithin an opening 262 formed between two spaced apart pins or camfollowers 264, 266. The cam followers 264, 266 are fixedly mounted to aninterior portion of the housing 102. A gear 268 is attachedcircumferentially about cam 254. The cam 254 is positioned such that thegear 268 is arranged in meshed engagement with drive gear 252. As shown,the rotational axis of the gear 268 is arranged parallel to therotational axis of drive gear 252. Rotation of drive gear 252 will, inturn, effect rotation of gear 268 and cam 256, and hence, shaft 116. Asthe cam 256 is rotated, its engagement with cam followers 264, 266 willalso cause the cam 256 to reciprocate thereby reciprocating shaft 116and needle 122. The reciprocal motion of the cam 254 is accommodated bygear 268 sliding in meshed engagement with the drive gear 252. Ifrotational motion of the shaft 116 is not desired, the shaft can besupported by the cam 256 using a bearing 218 in a similar arrangement asshown in the instrument 192 illustrated in FIG. 4.

[0096] The biopsy needle instrument of the present invention providesfor reciprocal and/or rotary motion of a needle under programmed controlduring the biopsy procedure. It may be desirable to couple the biopsyneedle instrument with a source of vacuum for aspiration of the tissuesample into needle 122. By way of example, as shown in FIG. 13, aT-connector 270 is attached between the shaft 116 and coupling device120 which is formed as part of the needle 122. The near end 271 of theT-connector 270 which is attached to the instrument 100 is closed off.Branch 272 of the T-connector 270 is connected to a conventional syringe274 by means of flexible tubing 276 having an on/off valve 277. While atissue sample is being collected in the needle 122, plunger 278 can bewithdrawn from within the syringe 274 to create vacuum within theT-shaped connector 270, which vacuum is maintained by closing on/offvalve 277. This, in turn, will draw the tissue sample into the needle122 which is now under vacuum. After the predetermined sampling cycle iscompleted, the needle 122 is removed from the patient's body and thetissue sample can then be dispensed from the need by means of advancingthe plunger 278 of the syringe 274 after opening the on/off valve 277.

[0097] Referring to FIG. 14, there is graphically illustrateddisplacement or thrust distance of the needle 122 in relationship to onerevolution of cam 156, 254 or cam track 202. As shown, the maximumextended travel or displacement of the needle 122 occurs at 180° ofrotation of the cam or cam track. By altering the angular relationshipbetween cam axis 172 and its rotational axis which corresponds to axis138, see FIG. 3A, the travel distance of the needle 122 can be changed.This is represented by the solid line and dashed line curves in FIG. 14.

[0098] Another embodiment of a cam 279 is shown in FIG. 15. The cam 279has one segment 280 extending 180° having its axis 282 perpendicular toaxis 138. Another equal segment 283 has its axis 284 at an angle to axis138. The cam 279 provides the needle travel distance profile as shown inFIG. 16. The travel distance provides a dwell period of 90° before andafter movement of the needle 122 during rotation of the cam 279.

[0099] Using the foregoing modifications and variations of the camprofiles, various combinations of these cam profiles can produce variousmotion of the needle 122. As shown in FIG. 17, there is initiallyprovided a dwell period followed by a high velocity extension of theneedle 122, followed by a slow retraction of the needle into theinstrument housing 102. In FIG. 18, a similar travel of the needle 122is produced, but without a dwell period. As shown in FIG. 19, the needle122 will have an initial low velocity extension, followed by a highvelocity retraction of the needle into the housing 102. From theforegoing, it should be understood that almost any profile can beachieved with reasonable ramp angles. It is to be noted that the higherthe ramp angle, which produces higher needle velocities, there isrequired more torque from the motor 130. This effect can be dampened bythe use of a flywheel.

[0100] Turning to FIG. 20, there is illustrated in cross-section a cam300 constructed in accordance with another embodiment of the presentinvention. The cam 300 includes a body 301 which forms a pair of spacedapart outwardly facing cam surfaces 302, 304 for respective engagementwith pins 161 which are attached to the shaft 116.

[0101] Referring to FIG. 21, cam 306 is provided with a circumscribingrecessed portion 308 which is bound by a pair of spaced apart slopingcam surfaces 310, 312. A pair of spaced apart pins 161 attached to shaft116 extend upwardly into the recessed portion 308 for respectiveengagement with the cam surfaces 310, 312. As shown in FIG. 22, a singlecam follower 314 may be received within the recessed portion 308. Thecam follower 314 has outwardly facing spaced apart surfaces 316, 318 forrespective engagement with cam surfaces 310, 312. As shown in FIG. 23,the cam 306 is provided with outwardly facing spaced apart sloping camsurfaces 320, 322 for respective engagement with spaced apart pins 161.

[0102] Referring to FIGS. 24-28, various modifications of the drive andcam assembly as shown in FIG. 11 will now be described. In each of theseembodiments, the cam assembly will be operative to effect both rotaryand reciprocal motion of shaft 116, and hence, needle 122 which isattached thereto. As shown in FIG. 24, the cam assembly 324 includes agear 268 to which there is attached on one side thereof a cam body 256.The cam body is provided with a circumscribing recessed portion 326defining a pair of spaced apart sloping cam surfaces 328, 330. A camfollower 314 attached to the housing 102 extends into the recessedportion 326 for engagement with the cam surfaces 328, 330.

[0103] Turning to FIG. 25, the cam assembly 331 includes gear 268provided with cam bodies 332, 334 supported on either side of the gear.A circumscribing recessed portion 335 defined by the diameter of gear268 and larger diameters of the cam bodies 332, 334, also define a pairof spaced apart sloping cam surfaces 336, 337. In accordance with thisarrangement, drive gear 252 by having a peripheral portion receivedwithin the recessed portion 335 functions as a cam follower, as well aseffecting rotation of gear 268 as a result of the meshed engagementtherewith.

[0104] Turning to FIG. 26, the cam assembly 338 includes a cam body 339having a circumscribing recessed portion 340. The cam body 339 isattached to one surface 342 of drive gear 252. The recessed portion 340defines a cam surface 344 opposing surface 342 of the drive gear 252which functions as a second cam surface. A cam follower 346 attached onone side to gear 268, and supporting on its other side shaft 116, hasits peripheral portion 348 received within the recessed portion 340. Thedrive gear 252 is maintained in meshed engagement with gear 268.

[0105] Turning to FIG. 27, the cam assembly 350 includes drive gear 252provided with cam bodies 352, 354 supported on either side of the drivegear. A circumscribing recessed portion 356 defined by the diameter ofthe drive gear 252 and the larger diameters of the cam bodies 352, 354,also define a pair of spaced apart sloping cam surfaces 358, 360. Inaccordance with this arrangement, gear 268 by having a peripheralportion received within the recessed portion 356 functions as a camfollower, as well as effecting rotation of shaft 116 as a result of themeshed engagement with the drive gear 252.

[0106] Turning to FIG. 28, the cam assembly 362 includes a cam follower264 attached to one side of drive gear 252. A cam body 366 having acircumscribing recessed portion 368 is attached to one surface 370 ofgear 268. The recessed portion 368 defines a cam surface 372 opposingsurface 370 of gear 268 which functions as a second cam surface. The camfollower 364 has a peripheral portion 374 received within the recessedportion 368 for engagement with the cam surfaces 370, 372. The drivegear 252 is maintained in meshed engagement with gear 268 for rotationand reciprocal motion of shaft 116 which is attached to the cam body366.

[0107] Referring to FIGS. 29 and 30, the cam assemblies are operativefor effecting only reciprocal motion of shaft 116, and hence the needle122. Referring to FIG. 29, the cam assembly 376 includes a cylindricalbody 378 having an internal bore 380 opening at one end thereof. Theother end is closed by wall 382 from which there extends shaft 116. Thebore 380 is circular in shape so as to rotatably receive a circularshaped cam body 384 which is attached to shaft 136 for rotation by meansof motor 130. The cam body 384 has a circumscribing recessed portion 386defining a pair of spaced apart sloping cam surfaces 388, 390. A camfollower 392 in the nature of a pin is attached to the body 378 andextends inwardly so as to be captured within the recessed portion 386.

[0108] By rotation of cam body 384, the cylindrical body 378 willreciprocate within the instrument 100. To prevent rotation of thecylindrical body 378, at least one, and preferably a pair of opposingpins 394 extend outwardly from the body 378. The pins 394 are receivedwithin longitudinal slots (not shown) formed within the housing 102. Inan alternate embodiment, the slots can be helical in nature, which willimpart rotary motion to the cylindrical body 378, and hence to theneedle 122.

[0109] Referring to FIG. 30, the cam body 384 is provided with a pair ofspaced apart regions of reduced diameter so as to form an outwardlyextending circumscribing cam 396 forming a pair of spaced apart camsurfaces 398, 400. The cam surfaces 398, 400 are respectively engaged bypins 392 extending from the cylindrical body 378.

[0110] Although the invention herein has been described with referenceto particular embodiments, it is to be understood that the embodimentsare merely illustrative of the principles and application of the presentinvention. For example, by suitable means such as cams and othermechanical assemblies known in the art, the end of the reciprocal shaft116, and hence the needle 122, can be made to orbit or follow a zigzagor other predetermined path during the thrust of the needle as thus fardescribed. It is therefore to be understood that numerous modificationsmay be made to the embodiments and that other arrangements may bedevised without departing from the spirit and scope of the presentinvention as defined by the claims.

What is claimed is:
 1. A medical instrument comprising a housing havingan opening at one end thereof; a first shaft within said housing forreciprocal motion, said first shaft having a front section and a rearsection, said front section of said shaft extending adjacent saidopening in said housing; a cam assembly within said housing, said camassembly comprising first and second cam followers arranged in spacedapart relationship on said first shaft, a cam arranged between saidfirst and second cam followers mounted on a rotatable second shaft, saidcam having outwardly facing first and second cam profiles respectivelyengaging an opposing one of said first and second cam followers, wherebysaid cam assembly upon rotation of said cam converting rotating motionof said second shaft to reciprocal motion of said first shaft.
 2. Theinstrument as claimed in claim 1, wherein said first shaft is arrangedalong a first axis and said second shaft is arranged along a second axisparallel to said first axis.
 3. The instrument as claimed in claim 1,further including a motor coupled to said second shaft for rotationthereof.
 4. The instrument as claimed in claim 1, wherein said first andsecond cam profiles are symmetrical.
 5. The instrument as claimed inclaim 1, wherein said first and second cam profiles are non-symmetrical.6. The instrument as claimed in claim 1, wherein said cam comprises acylindrical body having first and second spaced apart surfacesrespectively providing said first and second cam profiles.
 7. Theinstrument as claimed in claim 1, further including a coupling deviceattached to said front section of said first shaft extending outwardlyof said housing, said coupling device operative for releasableattachment of a needle thereto.
 8. The instrument as claimed in claim 7,further including a needle attached to said coupling device.
 9. Theinstrument as claimed in claim 1, further including a connector having aclosed end attached to said front section of said first shaft outwardlyof said housing, said connector operative for attachment of a vacuumsource thereto.
 10. The instrument as claimed in claim 9, furtherincluding a needle releasably coupled to said connector.
 11. Theinstrument as claimed in claim 1, further including electronic controlmeans for controlling the operation of said instrument.
 12. A medicalinstrument comprising a housing having an opening at one end thereof; areciprocating shaft within said housing, said reciprocating shaft havinga front section and a rear section, said front section of saidreciprocating shaft extending outwardly through said opening; a camassembly within said housing operatively coupled to said reciprocatingshaft, said cam assembly comprising a cam having first and second spacedapart outwardly facing cam profiles, a first cam follower on one side ofsaid cam in engagement with said first cam profile, and a second camfollower on the other side of said cam in engagement with said secondcam profile; and a motor operatively coupled to said cam for rotationalmovement of said cam, whereby said engagement of said first and secondcam profiles with said first and second cam followers during rotation ofsaid cam causes reciprocal movement of said reciprocating shaft.
 13. Theinstrument as claimed in claim 12, wherein said first and second camfollowers are mounted to said reciprocating shaft.
 14. The instrument asclaimed in claim 13, wherein said cam is mounted on a rotatable shaftwithin said housing.
 15. The instrument as claimed in claim 14, whereinsaid motor within said housing is coupled to said rotatable shaft forrotation thereof.
 16. The instrument as claimed in claim 12, furtherincluding a needle attached to said front section of said reciprocatingshaft outwardly of said housing.
 17. The instrument as claimed in claim16, further including a coupling device for releasably coupling saidneedle to said reciprocating shaft.
 18. The instrument as claimed inclaim 12, wherein said first and second cam followers are fixedlyattached to said housing on opposite sides of said cam.
 19. Theinstrument as claimed in claim 18, wherein said cam is mounted on saidreciprocating shaft.
 20. The instrument as claimed in claim 19, whereinsaid motor includes a shaft having an axis parallel to an axis of saidreciprocating shaft.
 21. The instrument as claimed in claim 19, furtherincluding a first gear within said housing rotatable by operation ofsaid motor, and a second gear arranged circumferentially about said cam,said first and second gears being in sliding meshed engagement, wherebyrotation of said first gear causes rotation of said cam for rotation ofsaid reciprocating shaft, and the engagement of said first and secondcam followers with said cam causing reciprocating movement of saidreciprocating shaft.
 22. The instrument as claimed in claim 21, whereinsaid cam has an axis of rotation colinear with an axis of rotation ofsaid reciprocating shaft and parallel to an axis of rotation of saidfirst gear.
 23. The instrument as claimed in claim 12, where said firstand second cam profiles control the stroke length of said reciprocatingshaft.
 24. The instrument as claimed in claim 12, further including aneedle attached to said front section of said shaft outwardly of saidhousing, and means for creating a vacuum in said needle.
 25. Theinstrument as claimed in claim 12, further including electronic controlmeans for controlling the operation of said instrument.
 26. A medicalinstrument comprising a housing having an opening at one end thereof; areciprocating shaft along a first axis within said housing, saidreciprocating shaft having a front section and a rear section, saidfront section of the shaft extending outwardly through said opening; acam assembly within said housing comprising a cam having first andsecond spaced apart cam profiles, a first cam follower on one side ofsaid cam in engagement with said first cam profile, and a second camfollower on the other side of said cam in engagement with said secondcam profile; and a motor on a second axis within said housingoperatively coupled to said cam for rotational movement of said cam,said second axis offset from said first axis, whereby rotation of saidcam causes reciprocal movement of said reciprocating shaft.
 27. Theinstrument as claimed in claim 26, wherein said first and second camfollowers are mounted to said reciprocating shaft.
 28. The instrument asclaimed in claim 27, wherein said cam is mounted on a rotatable shaftwithin said housing.
 29. The instrument as claimed in claim 26, furtherincluding a needle attached to said front section of said shaftoutwardly of said housing.
 30. The instrument as claimed in claim 29,further including a coupling device for releasably coupling said needleto said shaft.
 31. The instrument as claimed in claim 26, wherein saidfirst and second cam followers are fixedly attached to said housing onopposite sides of said cam.
 32. The instrument as claimed in claim 31,wherein said cam is mounted on said reciprocating shaft.
 33. Theinstrument as claimed in claim 32, further including a motor within saidhousing operatively coupled to said cam for rotation thereof.
 34. Theinstrument as claimed in claim 33, further including a first gear withinsaid housing rotatable by operation of said motor, and a second geararranged circumferentially about said cam, said first and second gearsbeing in sliding meshed engagement, whereby rotation of said first gearcauses rotation of said cam for rotation of said reciprocating shaft,and the engagement of said first and second cam followers with said camcausing reciprocating movement of said reciprocating shaft.
 35. Theinstrument as claimed in claim 26, wherein said first and second camprofiles are non-symmetrical.
 36. The instrument as claimed in claim 26,where said first and second cam profiles control the stroke length ofsaid reciprocating shaft.
 37. The instrument as claimed in claim 26,further including a needle attached to said front section of said shaftoutwardly of said housing, and means for creating a vacuum in saidneedle.
 38. The instrument as claimed in claim 26, further includingelectronic control means for controlling the operation of saidinstrument.
 39. A medical instrument comprising a housing having anopening at one end thereof; a shaft within said housing for reciprocalmotion, said shaft having a front section and a rear section, said frontsection of said shaft extending outwardly through said opening of saidhousing; a motor within said housing; and a cam assembly within saidhousing comprising a cam operationally coupled to said motor forrotational movement of said cam, said cam having a track and a camfollower fixed to said housing and received within said track; wherebyreceipt of said cam within said track during rotation of said cam bysaid motor causes reciprocal movement of said shaft.
 40. The instrumentas claimed in claim 39, further including a coupling attached to saidmotor and coupled to said cam.
 41. The instrument as claimed in claim40, wherein said cam comprises a body having a bore therein and saidcoupling sliding received within said bore.
 42. The instrument asclaimed in claim 41, further including means for preventing relativerotation between said coupling and said cam when said coupling isreceived within said bore, whereby rotation of said coupling causesrotation of said cam and reciprocal and rotational motion of said shaft.43. The instrument as claimed in claim 42, wherein said shaft isattached to said cam in longitudinal alignment therewith.
 44. Theinstrument as claimed in claim 39, further including a bearing couplingsaid shaft to said cam, whereby rotation of said cam causes reciprocalmotion of said shaft while said bearing prevents rotational motion ofsaid shaft.
 45. The instrument as claimed in claim 39, further includinga needle releasably coupled to said shaft outwardly of said housing. 46.The instrument as claimed in claim 45, further including means forcreating a vacuum in said needle.
 47. The instrument as claimed in claim39, further including electronic control means for controlling theoperation of said instrument.
 48. The instrument as claimed in claim 39,wherein said cam assembly controls the stroke length of said shaft.